new script to take a domain name off of a fully qualified hostname.

diff --git a/scripts/networking/prune_domain.sh b/scripts/networking/prune_domain.sh
new file mode 100644 (file)
index 0000000..3b06f74
--- /dev/null
+++ b/scripts/networking/prune_domain.sh
@@ -0,0 +1,60 @@
+#!/bin/bash
+
+# takes the domain name off of the hostname provided and outputs just the
+# short name for the host.  the host is the first parameter, and the domain
+# name is the second, but both are optional.  if missing, this script uses
+# the local machine's information to print a hostname stripped of domain.
+
+source "$FEISTY_MEOW_SCRIPTS/core/functions.sh"
+
+#ha, should look back and see what other cool stuff hecho used to do.
+function hecho()
+{
+  echo $* 1>&2
+}
+
+export host="$1"; shift
+if [ -z "$host" ]; then
+  host="$(hostname)"
+fi
+export DOMAIN_NAME="$1"; shift
+if [ -z "$DOMAIN_NAME" ]; then
+  # set the domain name based on what's found in the resolv.conf file, where
+  # dns info is often found.
+  DOMAIN_NAME=$(grep -i search </etc/resolv.conf | tail -1 | sed -n -e 's/domain.\(.*\)$/\1/p')
+  if [ -z "$DOMAIN_NAME" ]; then
+    # second try, searching out the search domain as a suitable replacement
+    # for the actual domain being specified.
+    DOMAIN_NAME=$(grep -i search </etc/resolv.conf | tail -1 | sed -n -e 's/search.\(.*\)$/\1/p')
+  fi
+  # oh well, we don't know what the heck the domain is.
+  if [ -z "$DOMAIN_NAME" ]; then
+    hecho "The domain name cannot be intuited from the system and was not provided"
+    hecho "on the command line, so we have to give up."
+#hmmm: below starts to look reusable.
+    hecho "   host is '$host', domain is'$DOMAIN_NAME'."
+    exit 1
+  fi
+fi
+
+#hecho domain is $DOMAIN_NAME
+#hecho name before was $host
+
+domlen=${#DOMAIN_NAME}
+namelen=${#host}
+
+if [ $namelen -le $(($domlen+1)) ]; then
+  hecho "The hostname is too short to remove the domain name."
+  hecho "   host is '$host', domain is'$DOMAIN_NAME'."
+  exit 1
+fi
+
+#hecho domain name length is $domlen
+
+# we go back one more character than needed for the domain name, so we can consume the dot.
+chopname=${host:0:(($namelen - $domlen - 1))}
+
+#hecho "chopped name is '$chopname'"
+
+echo $chopname
+